Extract methods to make code cleaner

Author: ArBridgeman

exasol/toolbox/config.py

@@ -1,4 +1,5 @@
 import inspect
+from collections.abc import Callable
 from typing import (
     Annotated,
     Any,
@@ -19,34 +20,50 @@
 from exasol.toolbox.util.version import Version
 
 
+def get_methods_with_hook_implementation(
+    plugin_class: type[Any],
+) -> tuple[tuple[str, Callable], ...]:
+    """
+    Get all methods from a plugin_class which were specified with a @hookimpl.
+    """
+    return tuple(
+        (name, method)
+        for name, method in inspect.getmembers(plugin_class, inspect.isroutine)
+        if hasattr(method, PLUGIN_ATTR_NAME)
+    )
+
+
+def filter_not_specified_methods(
+    methods: tuple[tuple[str, Callable], ...],
+) -> tuple[str, ...]:
+    """
+    Filter methods which were specified with a @hookimpl but where not specified
+    in `exasol.toolbox.nox.plugins.NoxTasks`.
+    """
+    return tuple(name for name, _ in methods if name not in METHODS_SPECIFIED_FOR_HOOKS)
+
+
 def validate_plugin_hook(plugin_class: type[Any]):
     """
-    Checks methods in a class for at least one specific pluggy @hookimpl marker
-    and verifies that this method is also specified in
-    `exasol.toolbox.nox.plugins.NoxTasks`.
+    Validate methods in a class for at least one pluggy @hookimpl marker and verifies
+    that this method is also specified in `exasol.toolbox.nox.plugins.NoxTasks`.
     """
-    has_hook_implementation = False
-    not_specified_decorated_methods = []
-    for name, method in inspect.getmembers(plugin_class, inspect.isroutine):
-        if hasattr(method, PLUGIN_ATTR_NAME):
-            has_hook_implementation = True
-            if name not in METHODS_SPECIFIED_FOR_HOOKS:
-                not_specified_decorated_methods.append(name)
-
-    if not has_hook_implementation:
+    methods_with_hook = get_methods_with_hook_implementation(plugin_class=plugin_class)
+
+    if len(methods_with_hook) == 0:
         raise ValueError(
             f"No methods in `{plugin_class.__name__}` were found to be decorated"
             "with `@hookimpl`. The `@hookimpl` decorator indicates that this"
             "will be used with pluggy and used in specific nox sessions."
             "Without it, this class does not modify any nox sessions."
         )
 
-    if not_specified_decorated_methods:
+    if not_specified_methods := filter_not_specified_methods(methods_with_hook):
         raise ValueError(
-            f"{len(not_specified_decorated_methods)} method(s) were "
+            f"{len(not_specified_methods)} method(s) were "
             "decorated with `@hookimpl`, but these methods were not "
             "specified in `exasol.toolbox.nox.plugins.NoxTasks`: "
-            f"{not_specified_decorated_methods}. The `@hookimpl` decorator indicates "
+            f"{not_specified_methods}. The `@hookimpl` decorator indicates "
             "that these methods will be used by pluggy to modify specific nox sessions."
             "If the method was not previously specified, then no nox sessions will"
             "be modified. The `@hookimpl` is only used by nox sessions provided by the"

test/unit/config_test.py

@@ -121,7 +121,7 @@ def test_raises_exception_method_with_hook_not_specified():
         with pytest.raises(ValidationError) as ex:
             BaseConfig(plugins_for_nox_sessions=(WithNotSpecifiedHook,))
         assert "1 method(s) were decorated with `@hookimpl`, but" in str(ex.value)
-        assert "['not_specified_anywhere']" in str(ex.value)
+        assert "('not_specified_anywhere',)" in str(ex.value)
 
     @staticmethod
     def test_raises_exception_without_hook():